The superhero tentpole is assured of becoming the first title of 2016 to cross $1 billion, continuing Disney's domination; elsewhere, 'Mother's Day' makes something of a comeback in its second weekend, timed to the actual holiday.

Marvel Studios and Disney's Captain America: Civil War launched to a mighty $181.8 million in North America over the weekend, kicking off the summer box office in high style and scoring the fifth-best opening of all time, as well as the top launch of 2016 to date.

Overseas, where it bowed last weekend, Civil War took in another $220 million — including $96 million in China — for a foreign total of $496.6 million and worldwide haul of $678 million after just 12 days in release. Directed by Anthony and Joe Russo, Civil War is all but assured of becoming the first release of 2016 to top the $1 billion mark at the worldwide box office.

The critically acclaimed superhero film continues Disney domination, between Lucasfilm's Star Wars: The Force Awakens (the movie opened in late December but stayed a huge player in the first part of the new year), The Jungle Book and Zootopia.

In terms of opening-weekend rankings, Civil War shot past Iron Man 3 ($174 million) to come in at No. 5 behind Star Wars: The Force Awakens ($248 million), Jurassic World ($208.8 million), The Avengers ($207.4 million) and Avengers: Age of Ultron ($191.3 million), not accounting for inflation. Put another way, Disney claims four of the five top openings (Jurassic World was released by Universal).

Civil War is more Avengers-like in feel than the previous two stand-alone Captain America films, and it showed: Captain America: The Winter soldier debuted to $95 million, while Captain America: The First Avenger opened to $65.1 million.

Civil War sees the Avengers fractured and forced to choose sides between Captain America/Steve Rogers (Chris Evans) and Iron Man/Tony Stark (Robert Downey Jr.) when the government tries to control the superheroes. Many of the other Avengers stars appear in the movie,including Scarlett Johansson, Anthony Mackie and Jeremy Renner. Plus, new additions to the Marvel cinematic universe — Black Panther (Chadwick Boseman) and Spider-Man/Peter Parker (Tom Holland) — make their debuts.

"There's overwhelming momentum to this universe. There has been a consistent approach by Kevin Feige and his team at Marvel to deliver consistent, high-quality content," said Disney distribution chief Dave Hollis. "And with little competition between now and Memorial Day, we are set up to do tons of business."

Costing $250 million to make, Civil War is the 13th title in the Marvel Cinematic Universe. In addition to being embraced by critics — it currently shows 91 percent fresh rating on Rotten Tomatoes, a strong number for a popcorn movie — it also won over audiences, who gave it an A CinemaScore. And moviegoers under the age of 25 gave it an A+.

The tentpole skewed male (59 percent), with adults making up 69 percent of ticket buyers, followed by families (20 percent) and teens (11 percent).

Heading into the weekend, Disney tried to keep expectations in check by suggesting a domestic debut in the $175 million range. Many box-office analysts were more bullish, saying it had a shot of crossing $190 million, on par with Age of Ultron. Still, the movie did not have Avengers in the title, and its initial performance is considered a huge win by analysts and rival studios.

Garry Marshall's ensemble holiday comedy Mother's Day seemed to get a huge boost from the actual holiday, and was up 7.6 percent in its second weekend, grossing $9 million for a domestic total of $20.7 million. That's a major comeback after debuting to a troubled $8.4 million. Open Road Films is releasing the movie.

Mother's Day placed No. 3 behind Civil War and TheJungle Book, which remained a formidable force in its fourth weekend, grossing $21.9 million for a domestic total of $285 million. Internationally, it grossed another $24.1 million mark as it races toward the $500 million mark, finishing Sunday with a foreign cume of $491.2 million. Worldwide, Jon Favreau's film has grossed $776.2 million.

Universal's The Huntsman: Winter's War followed at No. 4, but continued to fall steeply in North America, taking in $3.6 million in its third weekend for a domestic total of $40.4 million. The pic is faring better overseas, grossing $105.9 million, but its global total of $146.3 million still is considered a major disappointment.

Elsewhere, Keanu tumbled 67 percent its second outing to $3.1 million for a domestic total of $15.1. The modestly budgeted New Line comedy placed No. 5 domestically.

At the specialty box office, the English-language thriller A Bigger Splash opened in three theaters in New York and Los Angeles, taking in a $100,000 for a location average of $22,000, the second best of the weekend after Civil War ($43,017). The film, which first debuted at the 2015 Venice Film Festival, stars Tilda Swinton, Matthias Schoernaerts, Ralph Fiennes and Dakota Johnson and is being released domestically by Fox Searchlight.

And a year after it won the Palme d'Or at the 2015 Cannes Film Festival, Dheepan made its U.S. theatrical debut on two screens in New York, grossing $22,760 for a location average of $11,380. IFC/Sundance Selects will open the drama in Los Angeles this coming weekend, and then keep expanding into other markets.

May 8, 10 a.m. A previous version of this story incorrectly stated the percentage gain for Mother's Day. THR regrets the error.